def test_set_optimizer_to_none(self):
"""Tests that setting the optimizer to None results in the default behavior"""
vqd = VQD(
k=1,
ansatz=self.ryrz_wavefunction,
optimizer=L_BFGS_B(),
quantum_instance=self.statevector_simulator,
)
vqd.optimizer = None
self.assertIsInstance(vqd.optimizer, SLSQP)
def test_vqd_optimizer(self):
"""Test running same VQD twice to re-use optimizer, then switch optimizer"""
vqd = VQD(
k=2,
optimizer=SLSQP(),
quantum_instance=QuantumInstance(
BasicAer.get_backend("statevector_simulator")),
)
def run_check():
result = vqd.compute_eigenvalues(operator=self.h2_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=3)
run_check()
with self.subTest("Optimizer re-use"):
run_check()
with self.subTest("Optimizer replace"):
vqd.optimizer = L_BFGS_B()
run_check()